Morphology and herbivory of Egregia menziesii at sites from California to Washington

Herbivores can drastically alter the morphology of macroalgae by directly consuming tissue and by inflicting structural wounds. Wounds, in particular, can result in large amounts of tissue breaking away from macroalgae, amplifying the damage initially caused by herbivores. Herbivores that commonly wound macroalgae often only occur over a portion of a macroalga’s lifespan or geographic range. However, we know little about the influence of these periodic or regional occurrences of herbivores on the large-scale seasonal and geographical patterns of macroalgal morphology. We used the intertidal kelp Egregia menziesii to investigate how the kelp’s morphology and the prevalence of two prominent kelp-wounding herbivores (limpets and gammarid amphipods) changed over two seasons (spring and summer) and over the northern extent of the kelp’s geographic range (six sites from central California to northern Washington). Wounds from limpets and amphipods often result in the kelp’s fronds being p...植食动物可通过直接啃食藻体组织与造成结构性损伤，极大改变大型藻类的形态特征。此类损伤往往会导致大量藻体组织脱落，进一步放大植食动物最初造成的破坏。通常会对大型藻类造成损伤的植食动物，往往仅在藻类生命周期的特定阶段，或是其地理分布范围的局部区域出现。然而，目前学界对这类周期性或区域性出现的植食动物，如何影响大型藻类形态的大尺度季节与地理分布格局，仍知之甚少。本研究以潮间带海带（Egregia menziesii）为研究对象，探究该海带的形态特征，以及两种主要造伤植食动物——帽贝（limpets）与钩虾（gammarid amphipods）的发生频次，在两个季节（春季与夏季）以及该海带地理分布范围的北部区域（从加利福尼亚中部至华盛顿北部的6个采样点）内的变化情况。帽贝与钩虾造成的损伤往往会导致该海带的叶状体出现……